The invention relates to a spider for universal-joint arrangements for prop shafts suitable for the transmission of torque.
Spiders for use in universal-joint shaft arrangements are known in a number of embodiments. As a general rule, the design and physical form of the geometry of the spider depends on the concrete constructive conditions and the desired mounting in a link yoke. Document DE 196 01 290 A1 is referenced as a representative example. The universal-joint shaft arrangement described therein comprises a spider, two link yokes provided to mount the pins of the spider, whereby each pin of the spider is mounted by means of a bearing arrangement, comprising a radial bearing with an outer ring and an inner ring and an axial bearing, in an attached yoke eye of the link yoke. Furthermore, an external collar, which is first in the installation position in the axial direction and directed towards the pin axis of the pin mounted in the link yoke and at least indirectly forms an axial stop for the fit of the inner ring in the frontal area of the pin, is attached to the inner ring. The first outer collar attached to the inner ring of the radial bearing can be connected in a force- and/or form-fitting manner with the pins mounted in the link yoke and/or is partially reinforced by the pins mounted in the link yoke. A second inner collar is attached to the inner ring in the installation position in the axial direction and extends radially away from the pin axis of the pin mounted in the link yoke. The inner collar of the inner ring thereby forms at least indirectly the outer contact surface of the axial bearing in the axial direction. Furthermore, the outer ring of the radial bearing also has a first inner collar in the axial direction, which extends radially in the direction of the pin axis of the pin mounted in the link yoke. The inner collar of the outer ring of the radial bearing thereby forms at least indirectly the inner contact surface of the axial bearing in the axial direction. The lubricant supply of the bearing arrangement is further sealed off from the environment via a sealing arrangement, which is reinforced by the pin root and is arranged between the inner ring and the outer ring of the axial bearing. However, the replacement of these individual seals requires the complete dismantling of the entire bearing assembly. This can, in particular in the case of very large universal-joint shafts, lead to considerable problems, in particular due to the amount of time required. Furthermore, the dismantling of the entire bearing arrangement can also lead to the damaging of other individual elements, in particular the other parts of the seals. There are known versions with seal holders carrying the seal; however, as a general rule, these are reinforced by the link yoke or are attached to it. Deformations of this part thus have a negative effect on the actual sealing function.
Supports of the seal holder on the spider are described in the document EP 1 213 502 A1, the unpublished WO 03/102435 A1 as well as the documents U.S. Pat. No. 4,664,643 and U.S. Pat. No. 6,059,663. EP 1 213 502 A1 discloses an embodiment of a spider with a cube-shaped base body, on which the seal holder is supported. It carries the seal. The seal holder lies against the base body. This is designed such that the immobilization is determined by the type of seal. Relative movements caused by deformations cannot be excluded, which in turn leads to the damaging of the seal surfaces. Furthermore, the seal holder is arranged below the radial bearing in the axial direction such that this space is to be taken into consideration when arranging the spider and the bearing assembly.
The U.S. Pat. No. 4,664,643 discloses a sealing device, which is designed as an integral unit. A seal holder is not provided. The seal is connected in a form-fitting manner with the pin.
U.S. Pat. No. 6,059,663 discloses a version with seal holder, which is supported in the bearing bushing of the radial bearing. Deformations of the bearing bushing are also transferred to the seal holder. The seal function is thus not always guaranteed.